From 7071d8a28e661ae459070e56767db64bce47b05b Mon Sep 17 00:00:00 2001 From: Lucas De Marchi Date: Thu, 4 Oct 2012 17:42:33 -0300 Subject: [PATCH] gdbus: Fix invalid memory access while unregistering If an interface is added and removed on the same mailoop iteration, ObjectManager would try to send InterfacesAdded signal while running the idler because the interface was added to data->added list. This is easily reproduced by forcing an error path in a plugin registration, like on sap_server_register(), resulting in the following error: ==11795== Invalid read of size 4 ==11795== at 0x496F592: dbus_message_iter_append_basic (dbus-message.c:2598) ==11795== by 0x117B39: append_interface (object.c:554) ==11795== by 0x48955E7: g_slist_foreach (gslist.c:840) ==11795== by 0x11923B: process_changes (object.c:592) ==11795== by 0x11956D: generic_unregister (object.c:980) ==11795== by 0x4973BAC: _dbus_object_tree_unregister_and_unlock (dbus-object-tree.c:516) ==11795== by 0x4965240: dbus_connection_unregister_object_path (dbus-connection.c:5776) ==11795== by 0x1178A5: object_path_unref (object.c:1219) ==11795== by 0x118517: g_dbus_unregister_interface (object.c:1344) ==11795== by 0x19AF5B: sap_exit (sap.c:385) ==11795== by 0x13E9E2: sap_server_register (server.c:1428) ==11795== by 0x13C092: sap_server_probe (manager.c:44) With this patch we don't send the InterfacesAdded signal, removing it from data->added while unregistering. --- gdbus/object.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/gdbus/object.c b/gdbus/object.c index c63a26d..444728c 100644 --- a/gdbus/object.c +++ b/gdbus/object.c @@ -657,6 +657,17 @@ static gboolean remove_interface(struct generic_data *data, const char *name) return TRUE; } + /* + * Interface being removed was just added, on the same mainloop + * iteration? Don't send any signal + */ + if (g_slist_find(data->added, iface)) { + data->added = g_slist_remove(data->added, iface); + g_free(iface->name); + g_free(iface); + return TRUE; + } + data->removed = g_slist_prepend(data->removed, iface->name); g_free(iface); -- 2.7.4